Printing apparatus, print control method, and recording medium storing print control program therein

ABSTRACT

A printing apparatus discriminates whether received print data is print data converted into a job packet constructed by a header portion and a data portion or print data which is not converted into a job packet and switches the processing operation in accordance with the print data.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a printing apparatus for processing print datawhich is transmitted from a host computer to generate the print data inaccordance with an instruction of the user, generating image data, andactually printing onto a medium such as a paper or the like. Theinvention also relates to a print control method of such a printingapparatus and a recording medium in which a print control program forsuch a print control method has been stored.

2. Related Background Art

A printing system which satisfies functions such that not only aprinting apparatus prints print data that is generated from a hostcomputer but also an information obtaining and an environmental settingof the printing apparatus are performed from the host computer has beenknown.

FIG. 1 is a diagram for explaining a first print data processing methodembodying a method of performing an information obtaining and anenvironmental setting of a printing apparatus from a host computer.

In FIG. 1, reference numeral 100 denotes a host computer; 150 a printingapparatus; and 180 a predetermined communication medium for connectingthe host computer 100 and printing apparatus 150.

Further, the host computer 100 is constructed by: an application section101 for providing a graphic user interface to the user and generatingimage data adapted to a purpose of the user; a printer driver 102 forconverting the image data generated by the application section 101 intopage description language (hereinafter, abbreviated to PDL) data whichcan be printed by the printing apparatus 150; a transmission buffer 103for temporarily storing the PDL data formed by the printer driver 102;an I/F driver 104 for transmitting the PDL data stored in thetransmission buffer to the printing apparatus 150 and transmitting andreceiving information to/from the printing apparatus 150; and a utilitysection 105 for obtaining the information of the printing apparatus 150and providing it to the graphic user interface and for changing theenvironmental setting of the printing apparatus 150 in accordance with ademand of the user.

The printing apparatus 150 is constructed by: an I/F driver 151 forreceiving the PDL data and environmental setting transmitted from thehost computer 100 and transmitting the information of the printingapparatus 150; a reception buffer 152 for temporarily holding all of thedata received by the I/F driver 151 and serving as a buffer device of adelay of processes at the post stage; a JL parser 153 for analyzing thereception data and discriminating by a predetermined job controllanguage (hereinafter, abbreviated to JL) whether the host computer hasrequested to obtain the information of the printing apparatus or thehost computer has transmitted the PDL data, thereby distributingprocesses; a PDL translator 154 for performing a translating process ofthe PDL data distributed by the JL parser 153 and converting into adrawing object suitable to draw; a database 158 for storing theinformation of the printing apparatus set by the JL and providing theinformation to the JL parser and PDL translator 154; a drawing buffer155 for temporarily storing the drawing object formed by the PDLtranslator 154 until it is actually printed; a drawing section 156 forgenerating a bit map image by actually drawing the drawing objecttemporarily stored in the drawing buffer 155; and a printer engine 157for receiving a bit map image generated by the drawing section 156 andprinting into a media such as a paper or the like by a well-knownprinting technique.

The first print data processing method has the following two problems.First, there is a problem such that since a channel to transmit andreceive the print data (PDL data) and a channel to obtain theinformation of the printing apparatus are the same, the transmission andreception of the print data and the information obtaining cannot besimultaneously performed. Second, there is a problem such that since theprint data is recognized by the JL parser 153, the print datatemporarily stored in the reception buffer 152 is not recognized andmanagement information regarding this print data cannot be returned tothe host computer 100.

SUMMARY OF THE INVENTION

To solve the above problems in the first print data processing method,therefore, a second print data processing method is considered.

FIG. 2 is a diagram showing a construction of the second print dataprocessing method. In FIG. 2, reference numeral 200 denotes a hostcomputer; 250 a printing apparatus; and 280 a predeterminedcommunication medium for connecting the host computer 200 and printingapparatus 250.

The host computer 200 is constructed by: an application section 201 forproviding a graphic user interface to the user and generating image dataadapted to a purpose of the user; a printer driver 202 for convertingthe image data generated by the application section 201 into pagedescription language (hereinafter, abbreviated to PDL) data which can beprinted by the printing apparatus 250; a transmission buffer 203 fortemporarily storing the PDL data formed by the printer driver 202; a jobpacket generator 207 for generating a job packet from the PDL datastored in the transmission buffer 203; a utility section 205 forgenerating a management packet to obtain the information of the printingapparatus 250 and provide it to the graphic user interface and changethe environmental setting of the printing apparatus 250 in accordancewith a demand of the user; a logic channel controller 206 for furtherconverting a job packet and a management packet into packet data; and anI/F driver 204 for transmitting and receiving the job packet andmanagement packet which were further converted to the packet data by thelogic channel controller 206 to/from the printing apparatus 250. In theinvention, the PDL data converted to the job packet is referred to as ajob packet and the environmental set data converted to the job packet isreferred to as a management packet.

The printing apparatus 250 is constructed by: an I/F driver 259 forreceiving the job packet and management packet which were converted tothe packet data and transmitted from the host computer 200 andtransmitting a management packet for reply converted to the packet databy a logic channel controller 251; the logic channel controller 251 fortransmitting the job packet to a job pre-processor 253, transmitting themanagement packet to an information manager 260, and further convertingthe management packet for reply transmitted from the information manager260 into packet data; a reception buffer 254 for temporarily holding thePDL data and serving as a buffer device of a delay of processes at thepost stage; a database 252 for storing the equipment information of theprinting apparatus and job information to draw a print job; the jobpre-processor 253 for receiving the job packet and transferring the PDLdata to the reception buffer 254 by an operation code written in aheader of the job packet or setting information into the database 252;the information manager 260 for receiving the management packet,rewriting the information in the database 252 in accordance with anoperation code written in the management packet and the data, andforming a management packet for reply to provide the equipmentinformation regarding the printing apparatus 250 to the host computer200; a PDL translator 255 for performing a translating process of thePDL data and converting into a drawing object suitable to draw; adrawing buffer 256 for temporarily storing the drawing object until itis actually printed; a drawing section 257 for generating a bit mapimage by actually drawing the drawing object temporarily stored in thedrawing buffer 256; and a printer engine 258 for receiving a bit mapimage generated by the drawing section 257 and printing into a mediasuch as a paper or the like by a well-known printing technique.

According to the second print data processing method, the job packet ina data channel and the management packet in a management channel arefurther converted into packet data and two logic channels areconstructed on one physical channel (communication medium 280), so thatthe transmission and reception of the print data and the managingrequest can be simultaneously performed. Further, by converting into thejob packet which can be interpreted relatively easily as compared withthe PDL by the host computer 200 and by interpreting in the jobpre-processor at the front stage of the reception buffer, all of theprint jobs inputted to the printing apparatus can be managed. Theinformation managing request of the jobs from the host computer can besatisfied.

The transmission and reception of the data and the reception and replyof the information managing request can be performed in a real-timemanner by the second print data processing method and the print jobs canbe managed. On the contrary, however, it is a prerequisite that the jobpacket generator 207 and logic channel controller 206 are provided onthe host computer side. However, it is necessary to individually preparethose processing sections because an installing method differs everyoperating system of the host computer. If those processing sectionscannot be installed, unless the print by the first print data processingmethod so far is supported, the print is impossible.

Further, when they are connected to a network, there is a case where theconnection by the host computer which corresponds to only the firstprint data processing method and the connection by the host computerwhich corresponds to only the second print data processing methodmixedly exist.

In the second print data processing method, in the case where a Net Wareserver or the like is provided between the host computer and theprinting apparatus and a banner (headline) page has been set, the serverforms print data as data of the banner page separately from the printingsystem of the host computer. There is, consequently, a problem such thatthe job packet and PDL data mixedly exist in one job and the operationof the second print data processing method cannot be guaranteed.

It is, therefore, an object of the invention to provide a printingapparatus which can discriminate whether print data has been convertedinto a job packet or not and can switch a processing method inaccordance with the print data.

That is, to accomplish the above object, a printing apparatus of theinvention comprises:

receiving means for receiving print data; and

processing operation determining means for switching a first print dataprocessing method of processing print data which is not converted into ajob packet and a second print data processing method of processing printdata converted into a job packet in accordance with whether the printdata received by the receiving means has been converted into a jobpacket of a packet structure constructed by a header portion and a dataportion or not.

More preferably, in the printing apparatus of the invention, thereceiving means can receive both of the print data converted into a jobpacket and the print data which is not converted into a job packet.

Further preferably, the printing apparatus of the invention has datadiscriminating means for discriminating whether the print data receivedby the receiving means is the print data converted into a job packet orthe print data which is not converted into a job packet.

Further preferably, in the printing apparatus of the invention, theprint data converted into the job packet has identification informationin the header portion, and

the data discriminating means discriminates whether the identificationinformation is included in the print data received by the receivingmeans or not, thereby discriminating whether the print data is the printdata converted into the job packet or the print data which is notconverted into the job packet.

Further preferably, the printing apparatus of the invention has mixturedata discriminating means for discriminating whether the print datawhich is not converted into the job packet and the print data convertedinto the job packet mixedly exist in the print data received by thereceiving means or not, and

the processing operation determining means switches the print dataprocessing method in accordance with the mixedly existing print data onthe basis of a discrimination result of the mixture data discriminatingmeans.

Further preferably, the printing apparatus of the invention has mixturedata discriminating means for discriminating whether the print datawhich is not converted into the job packet and the print data convertedinto the job packet mixedly exist in the print data received by thereceiving means or not, and

the processing operation determining means switches the print dataprocessing method in accordance with the mixedly existing print data onthe basis of a discrimination result of the mixture data discriminatingmeans.

More preferably, in the printing apparatus of the invention, in the casewhere it is determined by the data discriminating means that the printdata received by the receiving means is not converted into the jobpacket and it is decided by the mixture data discriminating means thatthe print data converted into the job packet mixedly exists in the printdata, the processing operation determining means switches in a mannersuch that the print data until it is decided that the print dataconverted into the job packet exists is processed by the first printdata processing method and that the print data after it was determinedthat the print data converted into the job packet existed is processedby the second print data processing method.

More preferably, in the printing apparatus of the invention, in the casewhere the identification information is included in the print datareceived by the receiving means, the mixture data discriminating meansdetermines that the print data converted into the job packet mixedlyexists.

More preferably, the printing apparatus of the invention further hasselecting means for enabling the operation of the first print dataprocessing method to be forcedly selected.

More preferably, the printing apparatus of the invention further has jobpre-processor means for extracting data regarding a printing processfrom the print data converted into the job packet and storing into datastoring means.

More preferably, the printing apparatus of the invention further hasinformation managing means for, when the management data converted intothe job packet is received by the receiving means, rewriting theequipment information of the printing apparatus stored in theinformation storing means or the print job information or generatingreply data on the basis of the equipment information stored in theinformation storing means.

More preferably, the printing apparatus of the invention further haschannel control means for sending the data received by the receivingmeans to the information managing means in the case where the receiveddata is the management data converted into the job packet and forsending the received data to the processing operation determining meansin the case where it is the print data.

Although the means constructed in the printing apparatus have beenmentioned above, according to the invention, the print data processingapparatus can also support a part or all of the above construction. Theinvention also incorporates a print control method which is accomplishedby steps similar to the foregoing means and a recording medium on whicha program of the similar steps has been recorded.

According to the invention, the print data received by the receivingmeans and the environmental set data are distributed by the firstchannel control means to the processing operation determining means viaa data channel in case of the print data converted into the job packetand the print data which is not converted into the job packet and aredistributed to the information managing means via a management channelin case of the environmental set data converted into the job packet. Theprocessing operation determining means automatically switches theoperation of the printing system on the basis of the print data of thedata channel in accordance with a discrimination result about whetherthe print data is the print data converted into the job packet or not.Even in the case where the print data converted into the job packet andthe print data which is not converted into the job packet mixedly existin the print data, the processing operation determining means switchesthe operation of the printing system in accordance with the mixedlyexisting print data. That is, any one of the print data described by anordinary page description language and the print data converted into thejob packet can be selectively processed by the processing operationdetermining means. Even in a printing system which does not have jobpacket generating means and second channel control means, it is possibleto cope with the printing process.

According to the invention, by further having selecting means forenabling the first print data processing method of processing the printdata described by the page description language to be forcedly selected,an instruction from the operator can be preferentially reflectedirrespective of an automatic recognition by compatible operationdetermining means. Thus, even in the case where although the hostcomputer presumed the first print data processing method, the printingapparatus judges the data as data of the second print data processingmethod and processes it, a process can be designated as print data inthe first print data processing method.

The above and other objects and features of the present invention willbecome apparent from the following detailed description and the appendedclaims with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram for explaining a construction of a printing systemaccording to a first print data processing method;

FIG. 2 is a diagram for explaining a construction of a printing systemaccording to a second print data processing method obtained by improvingthe printing system according to the first print data processing method;

FIG. 3 is a diagram for explaining a construction of the firstembodiment;

FIG. 4 is a diagram for explaining a packet construction of a jobpacket;

FIG. 5 is a flowchart for explaining the operation of a compatibleoperation determiner in the first embodiment;

FIG. 6 is a constructional diagram for explaining a construction of thesecond embodiment;

FIG. 7 is a diagram showing a display example of an operation panel;

FIG. 8 is a flowchart for explaining the operation of a compatibleoperation determiner in the second embodiment;

FIG. 9 is a constructional diagram for explaining a construction of thethird embodiment;

FIG. 10 is a flowchart for explaining the operation of a compatibleoperation determiner in the third embodiment;

FIG. 11 is a diagram showing a memory map on a recording medium;

FIG. 12 is a diagram for explaining a laser beam printer;

FIG. 13 is a diagram for explaining an ink jet printer; and

FIG. 14 is a diagram for explaining a control construction to execute arecording control of an apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the invention will now be described hereinbelowwith reference to the drawings.

First Embodiment

FIG. 3 is a diagram showing a construction of the first embodiment ofthe invention.

In FIG. 3, reference numeral 320 denotes a host computer (functions asfirst print data generating means) presuming the first print dataprocessing method; 300 a host computer (functions as second print datagenerating means) presuming the second print data processing method; 350a printing apparatus; and 380 a predetermined communication medium forconnecting the host computer 300 and printing apparatus 350.

In this connecting form, the printing apparatus 350 does not becomeaware of whether the host computer which sent the print data is the hostcomputer 300 or 320.

Further, the host computer 320 presumes the first print data processingmethod and is constructed by: an application section 321 for providing agraphic user interface to the user and generating image data adapted toa purpose of the user; a printer driver 322 for converting the imagedata generated by the application section 321 into page descriptionlanguage (hereinafter, abbreviated to PDL) data which can be printed bythe printing apparatus 350; a transmission buffer 323 for temporarilystoring the PDL data formed by the printer driver 322; an I/F driver 324for transmitting the PDL data stored in the transmission buffer to theprinting apparatus 350 and transmitting an environmental setting of theprinting apparatus 350; and a utility section 325 for changing theenvironmental setting of the printing apparatus 350 in accordance with ademand of the user.

Further, the host computer 300 presumes the second print data processingmethod and is constructed by: an application section 301 for providing agraphic user interface to the user and generating image data adapted toa purpose of the user; a printer driver 302 for converting the imagedata generated by the application section 301 into page descriptionlanguage (hereinafter, abbreviated to PDL) data which can be printed bythe printing apparatus 350; a transmission buffer 303 for temporarilystoring the PDL data formed by the printer driver 302; a job packetgenerator 307 for generating a job packet from the PDL data stored inthe transmission buffer 303; a utility section 305 for generating amanagement packet to obtain the information of the printing apparatus350 and provide it to the graphic user interface and change theenvironmental setting of the printing apparatus 350 in accordance with ademand of the user; a logic channel controller 306 for setting a logicchannel to receive the job packet from the job packet generator 307 to adata channel, setting a logic channel to transmit and receive amanagement packet to/from the utility section 305 to a managementchannel, and further converting the job packet and the management packetinto packet data in order to convert those two logic channels into onephysical channel for transmitting and receiving data to/from theprinting apparatus 350; and an I/F driver 304 for transmitting andreceiving the job packet and management packet which were furtherconverted to the packet data by the logic channel controller 306 to/fromthe printing apparatus 350. The PDL data converted to the job packet isreferred to as a job packet and the environmental set data converted tothe job packet is referred to as a management packet.

The printing apparatus 350 is constructed by: an I/F driver 359 forperforming the reception of the print data and the environmental setdata transmitted from the host computers 300 and 320, the transmissionof equipment information of the printing apparatus 350, and the like; alogic channel controller 351 for, when the data received by the I/Fdriver 359 is the packet data from the host computer 300, dividing thepacket data into the job packet and the management packet and sendingthem to a compatible operation determiner 360 and an information manager361 via the data channel and the management channel, respectively, andfor sending the received data to the compatible operation determiner 360when it is the data from the host computer 320; a reception buffer 354for temporarily holding the PDL data and serving as a buffer device of adelay of processes at the post stage; a database 352 for storing adatabase of equipment of the printing apparatus and job information todraw a print job; the compatible operation determiner 360 for checkingthe print data received from the logic channel controller and switchingthe operations of the first print data processing method and the secondprint data processing method in accordance with a discrimination resultabout whether the print data is the job packet or not; a jobpre-processor 353 for receiving the job packet from the compatibleoperation determiner 360 and transferring the PDL data to the receptionbuffer 354 by an operation code written in a header of the job packet orsetting information into the database 352; the information manager 361for receiving the management packet sent to the management channel,rewriting the information in the database 352 in accordance with anoperation code written in the management packet and the data, andforming a management packet for reply to provide the informationregarding the printing apparatus 350 to the host computer 300; a PDLtranslator 355 for performing a translating process of the PDL data andconverting into a drawing object suitable to draw; a drawing buffer 356for temporarily storing the drawing object until it is actually printed;a drawing section 357 for generating a bit map image by actually drawingthe drawing object temporarily stored in the drawing buffer 356; and aprinter engine 358 for receiving a bit map image generated by thedrawing section 357 and printing into a media such as a paper or thelike by a well-known printing technique. The reception buffer 354 anddatabase 352 function as data holding means (predetermined database).

A structure of a job protocol will now be described.

The job protocol is a protocol constructed by the job packet which isgenerated by the job packet generator 307 of the host computer 300 andis standardized so that the recognition of the start of the job and thesetting of job attributes can be easily performed in the jobpre-processor of the printing apparatus 350. A communication isperformed by a request due to a request packet of the job packet and areply by a reply packet which will be explained hereinlater.

FIG. 4 is a table showing a packet structure of the job packet.

An axis of ordinate denotes a byte and an axis of abscissa indicates abit of each byte.

In the diagram, the operation code of the zeroth and first bytesindicates an ID of a length of 2 bytes showing a function of the packet.In the job packet, the following values can be taken.

0x0201 job start operation 0x0202 job attribute set operation 0x0204 PDLdata transmission operation 0x0205 job end operation

where, the above values are expressed by the hexadecimal notation andone byte is expressed by two digits (the expression of “0x” usuallyindicates the hexadecimal notation).

The block number of the second and third bytes is a number which is usedto make a correspondence between the request and the reply in case ofrequesting a reply from the side which transmitted the job packet.

For example, if an error packet of the block No.=2 is returned when thejob packets of the block Nos.=1, 2, 3 are continuously transmitted, whena reply is returned, the transmission side can specify that an erroroccurred in the job packet sent at the second time.

The parameter length of the fourth and fifth bytes relates to an areashowing a byte length of the data portion and can show 0 to 64 kbytes.

The sixth and seventh bytes relate to an area showing various flags ofthe job packet and the following values are shown.

Error Flag:

When this value is equal to 1, it means that some error occurred in theprinting apparatus. This flag is added to a reply packet that is sentfrom the printing apparatus to the host computer.

Notice Flag:

When this value is equal to 1, it means that a fact that the printingapparatus has some notice item is notified to the host computer insteadof a reply to the request packet from the host computer.

Continuation Flag:

When this value is equal to 1, it means that since all of the datacannot be inputted to the data portion, the remaining data is sent inthe next job packet. For the next job packet, the same operation code asthat of the previous packet has to be set.

Reply Request:

“1” is set in the case where a reply packet is necessary from the hostcomputer to the printing apparatus. When this value is equal to 0, therequest packet does not reply in the case where it is normallyprocessed. When an error occurs in the printing apparatus, a replypacket in which the error flag is set to 1 is always transmittedirrespective of 0/1 of the reply request.

A user ID of the eighth and ninth bytes and a password of the tenth andeleventh bytes relate to areas which are used for authentication when asecurity-like limitation is provided to the operation which can beperformed in the request packet. They do not exert an influence on theembodiment.

The twelfth and subsequent bytes relate to an area in which the datacorresponding to the operation code is stored.

In case of a job start operation and a job end operation, the data doesnot depend on them.

In case of a job attribute set operation, a job attribute ID and a jobattribute value to be set are set. The job attribute ID shows attributesregarding the job or an identifier corresponding to the environment. AnID corresponding to the attribute of the job that is specified byISO-10175 (DPA) has previously been allocated. The representative jobattributes are as follows.

0x0101 job name 0x0103 job owner name 0x016a job size

In case of a PDL data transmitting operation, the PDL data is inputtedto the data portion. Since the data of one job packet has up to themaximum size that can be stored into the parameter length, the data ofup to 64 kbytes can be stored and the further remaining data is dividedinto a plurality of PDL data transmitting operation and transmitted. Inthis case, 1 is set to the continuation flag.

In the above job packet structure, when the print data is transferred, aprocedure to certainly transmit the job start operation is used. The jobstart operation can be specified such that the operation code is set to0x0201, the packet length is set to 12 bytes, only the reply request isequal to 0 or 1 in the flag area, and the other flags are equal to 0.Therefore, when the print data is received, if the header of the printdata coincides with the above conditions, the printing apparatus 350determines that the operation is the job start operation of the jobpacket and can operate as a second print data processing method. On thecontrary, when the printing apparatus 350 receives the print data, ifthe header of the print data does not coincide with the aboveconditions, since this means that the job packet is not received, theprinting apparatus can operate as a first print data processing methodthat is compatible to the conventional one. The above determination isperformed by the compatible operation determiner 360.

Although the management packet is expressed by a packet structure ofFIG. 4 in a manner similar to the job packet, the values of theoperation codes differ.

FIG. 5 is a flowchart for explaining the operation of the compatibleoperation determiner 360.

The compatible operation determiner starts the operation upon activationof the printing apparatus and continues the process until the powersource is shut off.

In FIG. 5, the print data is received in step S501. The print data isgenerated from the host computer 300 or 320 and is sent via the logicchannel controller 351.

When the print data is received, a header of the print data is checkedin step S502 and is compared to see if it coincides with a packetstructure of the operation code or the like of the job start operation.

In step S503, if it is recognized that the header coincides with the jobstart operation (YES in step S503), the print data is sent to the jobpre-processor 353 in step S504.

Since the print data is sent to the job pre-processor 353, the print jobexecutes the operation as a second print data processing method.

Since the print data converted to the job packet has size informationshowing the size of the relevant job packet in the header portion, adelimiter of the print data converted into the job packet isdiscriminated from the size information. In step S505, a check is madeto see if the reception has been completed up to the delimiter of theprint data. If it is not completed (NO in step S505), the processingroutine is returned to step S504. If it is completed YES in S505), theprocessing routine is returned to first step S501 in the compatibleoperation determiner. The next print data is checked.

If it is recognized in step S503 that the header does not coincide withthe job start operation (NO in S503), the print data is sent to thereception buffer 354 in step S506. Since it is not transmitted throughthe job pre-processor, the relevant job performs the operation as afirst print data processing method.

When the reception of the print data is not completed in step S507 (NOin S507), the operation to return to step S506 is continued until thereceived print data is interrupted. When the received print data isinterrupted and the reception of the print data is completed (YES inS507), the processing routine is returned to first step S501 in thecompatible operation determiner and the next print data is checked.

As described above, according to the embodiment, the print data receivedby the receiving means is distributed by the channel control means tothe processing operation determining means via the data channel in caseof the print data converted into the job packet and the print data whichis not converted into a job packet and is distributed to the informationmanaging means via the management channel in case of the environmentalset data (management packet) converted into the job packet. Theprocessing operation determining means switches the operation of theprinting system in accordance with whether the print data is the printdata converted into the job packet or not on the basis of the datareceived from the data channel.

That is, any one of the print data described by the ordinary pagedescription language and the print data converted into the job packetcan be selectively processed by the processing operation determiningmeans. Even in case of a printing system which does not have the jobpacket generating means and the logic channel control means, it ispossible to cope with the printing process.

By further converting the job packet and the management packet into thepacket data and constructing two logic channels by one physical channel,the transmission and reception of the print data and the managingrequest can be simultaneously performed. The print data is convertedinto the job packet which can be interpreted relatively easily ascompared with the PDL by the host computer and the job packet isinterpreted by the job pre-processor means at the front stage of thereception buffer, so that all of the print jobs received by the printingapparatus can be managed and the information managing request of the jobfrom the host computer can be satisfied.

Second Embodiment

In the first embodiment, the discrimination about the first and secondprint data processing methods has been made by the job start operationof the job packet. However, there is some possibility that the printdata which is transmitted by the first print data processing method alsobecomes the same data as that of the job data operation of the jobpacket. In this case, there is a possibility that although the operationby the first print data processing method is expected, the data passesthrough the job pre-processor and the print is not normally performed.The second embodiment shows an example for preferably performing theprint in such a case.

FIG. 6 is a diagram showing a construction of the second embodiment ofthe invention. Since an outline of the second embodiment is similar tothat of FIG. 3, only portions newly added for the second embodiment willbe described. Reference numeral 662 denotes an operation panel forallowing the user to display and set an environment of the printingapparatus. The operation panel is connected to a database 652 and theset contents of the operation panel are reflected to the database 652.

In the second embodiment, the user intends to print by the first printdata processing method. However, to avoid a possibility of erroneousoperation such that the print is performed by the second print dataprocessing method, selecting means for designating whether the firstprint data processing method is forcedly used or not on the operationpanel is provided.

FIG. 7 shows an example of the setting of the operation panel. “Jobmanagement” on the first line is a keyword indicative of a set itemabout whether the second print data processing method is used or not.The second line shows a selection item about whether the second printdata processing method is used or not and “To use” or “Not to use” canbe selected. In case of “To use”, this means that the printing processto decide which one of the first and second print data processingmethods is used is “To use (is used)” by the discriminating process ofthe compatible operation determiner shown in the first embodiment. Incase of “Not to use”, this means that the first print data processingmethod is forcedly used.

The item set value of “Job management” set in the database is obtainedby the compatible operation determiner 660 and the operation isswitched.

FIG. 8 is a flowchart for explaining the operation of the compatibleoperation determiner 660.

Only portions different from those in FIG. 5 of the first embodimentwill be explained. First in step S808, the compatible operationdeterminer obtains the set item value of “Job management” from thedatabase 652. In step S809, in the case where the set value indicates“Not to use” (the second print data processing method is not used butonly the first print data processing method is used), a process in stepS806 for unconditionally sending the print data to the reception bufferwithout discriminating whether the print data is the data converted intothe job packet or not is executed. Thus, the printing operationaccording to the use form can be selected on the basis of an instructionfrom the operator.

As described above, according to the embodiment, by further providingthe selecting means for enabling the first print data processing methodby the print data which is not converted into the job packet to beforcedly selected, the instruction from the operator can bepreferentially reflected irrespective of the automatic recognition bythe compatible operation determining means.

Thus, even in the case where although the host computer presumed thefirst print data processing method, it is decided in the compatibleoperation determiner that the print data is the data based on the secondprint data processing method and is processed, the process as print datain the first print data processing method can be designated.

Third Embodiment

According to the first embodiment, if the processing method of theoperation is once determined to be the first print data processingmethod or the second print data processing method by the compatibleoperation determiner, the printing system is not switched until thereception of the print data is completed.

The third embodiment shows an example of processing means for normallyprinting in the case where the print data of the first print dataprocessing method and the print data of the second print data processingmethod are mixedly sent into the print data.

FIG. 9 is a diagram showing a construction of a printing system of thethird embodiment.

In FIG. 9, reference numeral 900 denotes a host computer which presumesthe second print data processing method; 920 a print server; 950 aprinting apparatus; and 980 a predetermined communication medium forconnecting the host computer 900, print server 920, and printingapparatus 950.

The host computer 900 is similar to the host computer 300 in the firstembodiment.

The print server 920 is an apparatus for temporarily receiving aprinting request from the host computer 900 and transferring it to theprinting apparatus 950 and has a role to properly sequentially sendprinting requests from a plurality of host computers to the printingapparatus 950. The print server 920 is an existing apparatus and“Windows NT”, “Net Ware”, or the like is used.

The print server 920 is constructed by: an I/F driver 921 fortransmitting and receiving data to/from the network; a job receiver 922for receiving the printing request from the host computer 900 andsending the data to a transmission/reception buffer; thetransmission/reception buffer 923 for temporarily storing the data sentfrom the job receiver 922; and a job transmitter 924 for transmittingthe print data to the printing apparatus 950 via the I/F driver 921 inresponse to a request from the printing apparatus 950 when the printdata exists in the transmission/reception buffer 923.

The print server 920 can be set so as to add a banner page to the printdata. In this case, the job transmitter 924 adds banner page data to theheader of the print data. The banner page data is simple text datacomprising an alphanumeric code and a new-line character.

As for the job packet generated by the host computer 900, the bannerpage data is added to the header of the job packet when it passesthrough the print server 920. In the first embodiment, since the bannerpage data has been added, the job start operation cannot be recognizedin a compatible operation determiner 960, the apparatus operates as afirst print data processing method, and an erroneous operation isperformed.

To prevent the erroneous operation, the compatible operation determiner960 in the third embodiment is improved.

Although the printing apparatus 950 is similar to the printing apparatus350 in FIG. 3 in the first embodiment, the operation of the compatibleoperation determiner 960 differs. The operation of the compatibleoperation determiner 960 will now be described hereinbelow.

FIG. 10 is a flowchart for explaining the operation of the compatibleoperation determiner 960.

In FIG. 10, the print data is received in step 1001. The print data isgenerated from the host computer 900 and is sent via a logic channelcontroller 951. When the print data is received, in step 1002, theheader of the print data is checked and is compared to see if itcoincides with a packet structure of the job start operation.

In step 1003, if it is recognized that the header coincides with the jobstart operation (Yes in 1003), the processing routine advances to step1004 and the print data is sent to a job pre-processor 953.

When the print data is supplied to the job pre-processor 953, the printdata is printed by the second print data processing method.

Since the print data converted into the job packet has size informationindicative of the size of the job packet in the header portion, adelimiter of the print data converted into the job packet isdiscriminated from the size information. A check is made in step 1005 tosee if the reception of all of the print data up to the delimiter hasbeen completed. If it is not yet completed (No—1005), the processingroutine is returned to step 1004. If the reception is completed(Yes—1005), the processing routine is returned to first step 1001 of thecompatible operation determiner and the next print data is checked.

When it is recognized in step 1003 that the header of the print datadoes not coincide with the job start operation (No—1003), the contentsin the received print data are sequentially checked in step 1006. Acheck is made in step 1007 to see if the job start operation has beenincluded. If it is included (Yes—1007), the print data is sent to thereception buffer until the job start operation is found in step 1008. Asfor the print data after the job start operation was found, theprocessing routine advances to step 1004 and the operation by the secondprint data processing method is started.

When it is determined in step 1007 that the job start operation is notincluded in the print data (No—1007), all of the reception data is sentto the reception buffer in step 1009. A check is made in step 1010 tosee if all of the data has been received until the received print datais interrupted. If it is received (Yes—1010), the processing routine isreturned to the initial state in step 1001. When all of the data is notyet received (No—1010), the processing routine is returned to step 1006until all of the data is received. The print data is again checked.

As mentioned above, when it is decided in step 1003 that the print datais the data which is not converted into the job packet, processing steps1006, 1007, and 1008 are needed. However, if it is decided in step 1003that the print data is the data converted into the job packet, since thesize of the job packet can be discriminated by a parameter length of theheader of the job packet, the delimiter of the data which is specifiedby this size, namely, the completion of the reception of the job packetcan be accurately discriminated in step 1005. The processing routine isreturned to step 1001 and the print data after completion of thereception of the job packet is checked. Therefore, the processing stepslike 1006, 1007, and 1008 to check the contents in the print data areunnecessary.

As described above, according to the embodiment, in the case where theprint data by the first print data processing method and the print databy the second print data processing method are mixedly sent into theprint data, by switching the print data processing means in accordancewith the print data, the data can be normally printed.

In addition to the host computer which presumed the second print dataprocessing method, a host computer which presumes the first print dataprocessing method can be also connected by the predeterminedcommunication medium 980. In case of such a host computer, since thefirst print data processing method was presumed for the print data, evenif the banner page data is added by the print server 920, the operationis performed as a first print data processing method, so that theapparatus normally operates.

Even in the print data that is transmitted by the first print dataprocessing method, there is some possibility that it is the same data asthat of the job start operation of the job packet. In such a case, thereis a case where although the operation by the first print dataprocessing method is expected, the operation as a second print dataprocessing method is started. To preferably perform the print in thiscase, an operation panel 962 which can forcedly select the printingsystem can be also added in a manner similar to the second embodiment.

As an example of the operation of the printing system in this case, inthe flowchart of FIG. 10, before the operation in step 1001, operationssimilar to those in steps S808, S809, S806, and S807 in the flowchart ofFIG. 8 are added. That is, the following operations are added. The setitem value of “Job management” is obtained from the database 952. Whenthe set value indicates “Not to use” (the second print data processingmethod is not used but only the first print data processing method isused), a process to unconditionally send the print data to the receptionbuffer is performed without checking whether the print data is the dataconverted into the job packet or not. When the set value shows “To use”,the processing routine advances to step 1001 and subsequent steps andthe print data is checked.

Other Embodiments

The invention can be applied to a system constructed by a plurality ofequipment (for example, a host computer, an interface device, a reader,a printer, and the like) or can be also applied to an apparatuscomprising one equipment (for instance, a copying apparatus, a facsimileapparatus, or the like).

It will be obviously understood that the object of the invention isaccomplished by a method whereby a storing medium in which program codesof software to realize the functions of the foregoing embodiments havebeen recorded is supplied to a system or an apparatus and a computer (ora CPU or an MPU) of the system or apparatus reads out and executes theprogram codes stored in the storing medium.

In this case, the program codes themselves read out from the storingmedium realize the functions of the embodiments mentioned above and thestoring medium in which the program codes have been stored constructsthe invention.

As a storing medium to supply the program codes, for example, it ispossible to use any one of a floppy disk, a hard disk, an optical disk,a magnetooptic disk, a CD-ROM, a CD-R, a magnetic tape, a non-volatilememory card, an ROM, and the like.

It will be obviously understood that the invention incorporates not onlya case where by executing read-out program codes by a computer, thefunctions of the embodiments mentioned above are realized but also acase where the OS (operating system) or the like which is operating onthe computer executes a part or all of the actual processes on the basisof instructions of the program codes and the functions of theembodiments mentioned above are realized by those processes.

Further, it will be obviously understood that the invention alsoincorporates a case where the program codes read out from the storingmedium are written into a memory provided for a function expanding boardinserted into a computer or a function expanding unit connected to thecomputer and, after that, a CPU or the like provided for the functionexpanding board or function expanding unit executes a part or all of theactual processes on the basis of instructions of the program codes andthe functions of the embodiments mentioned above are realized by thoseprocesses.

In case of applying the invention to the storing medium, the programcodes corresponding to the flowcharts described before are stored intothe storing medium. However, now simply explaining, each module shown ina memory map example of FIG. 11 is stored into the storing medium. It issufficient to store the program codes of at least the followingrespective modules into the storing medium: namely, “Print datareception module 1101; “First logic channel control module 1102”;“Compatible operation determination module 1103”; “Job pre-processingmodule 1104”; “Information management module 1105”; “PDL translationmodule 1106”; “Job packet generation module 1107”; “Utility module1108”; and “Second logic channel control module 1109”.

Explanation of Outline of Printing Apparatus

A laser beam printer can be also used as a printing apparatus 350.

FIG. 12 is a cross sectional view showing an internal structure of alaser beam printer (hereinafter, abbreviated to an LBP). The LBP caninput character pattern data or the like and print onto a recordingpaper.

In the diagram, reference numeral 1240 denotes an LBP main body forforming an image onto the recording paper as a recording medium on thebasis of the supplied character pattern or the like; 1200 an operationpanel on which switches for operation, an LED display, and the like arearranged; and 1201 a printer control unit for controlling the whole LBP1240 and analyzing the character pattern information or the like. Theprinter control unit 1201 mainly converts the character patterninformation into a video signal and generates to a laser driver 1202.

The component elements of the invention can be assembled into theprinter control unit 1201.

The laser driver 1202 is a circuit to drive a semiconductor laser 1203and switches on/off of a laser beam 1204 emitted from the semiconductorlaser 1203 in response to the inputted video signal. The laser beam 1204is swung to the right and left by a rotary polygon mirror 1205 and scanson an electrostatic drum 1206. Thus, an electrostatic latent image of acharacter pattern is formed on the electrostatic drum 1206. This latentimage is developed by a developing unit 1207 arranged around theelectrostatic drum 1206 and, after that, it is transferred onto therecording paper. Cut sheets are used as recording papers. The cut sheetrecording papers are enclosed in a paper cassette 1208 attached in theLBP 1240. Each paper is fed into the apparatus by a paper feed roller1209 and conveying rollers 1210 and 1211 and is conveyed to theelectrostatic drum 1206.

Although the laser beam printer has been described above as an exampleof the image forming apparatus of the embodiment, the invention is notlimited to it but can be also applied to an ink jet printer or the likewhich will be explained hereinlater.

FIG. 13 is a conceptual diagram of an ink jet recording apparatus IJRAto which the invention can be applied. In the diagram, a lead screw 5005rotates in an interlocking relation with a forward/reverse rotation of adriving motor 5013 through driving force transfer gears 5011 and 5009. Acarriage HC which is come into engagement with a spiral groove 5004 ofthe lead screw 5005 has a pin (not shown) and is reciprocated in thedirections shown by arrows a and b. An ink jet cartridge IJC is mountedon the carriage HC. Reference numeral 5002 denotes a paper pressingplate for pressing the paper onto a platen 5000 in the moving directionof the carriage, and 5007 and 5008 indicate photocouplers serving ashome position detecting means each for confirming the existence of acarriage lever 5006 in a region where each photocoupler is arranged andfor performing a switching of a rotating direction of the motor 5013 orthe like. Reference numeral 5016 denotes a member to support a capmember 5022 to cap the front surface of a recording head and 5015indicates sucking means for sucking the inside of the cap, therebyperforming a sucking and a recovery of the recording head via an opening5023 in the cap. Reference numeral 5017 denotes a cleaning blade and5019 indicates a member for enabling the blade to be moved in thefront/rear direction and those component elements are supported to amain body supporting plate 5018. The blade is not limited to a formshown in the diagram but another well-known cleaning blade can be alsoobviously applied to the embodiment. Reference numeral 5021 denotes alever to start the sucking in the sucking/recovery operation. The lever5021 moves in association with the movement of a cam 5020 adapted to become into engagement with the carriage. A driving force from the drivingmotor is transferred by well-known transfer means such as a clutchswitching or the like.

Any desired one of the capping, cleaning, and sucking/recoveryoperations can be performed at each corresponding position by theoperation of the lead screw 5005 when the carriage reaches a region onthe home position side. However, if a desired operation is performed ata well-known timing, any one of them can be applied to the embodiment.

A control construction to execute the recording control of the apparatusmentioned above will now be described with reference to a block diagramshown in FIG. 14. In the diagram showing the control circuit, referencenumeral 1700 denotes an interface to input a recording signal; 1701 anMPU; 1702 a program ROM to store a control program which is executed bythe MPU 1701; 1703 a dynamic type ROM to store various data (therecording signal, recording data that is supplied to the head, etc.);1704 a gate array to control a supply of recording data to a recordinghead 1708 and to control a data transfer among the interface 1700, MPU1701, and RAM 1703; 1710 a head carrier motor to convey the recordinghead 1708; 1709 a paper feed motor to feed the recording paper; 1705 ahead driver to drive the head; and 1706 and 1707 motor drivers to drivethe paper feed motor 1709 and head carrier motor 1710, respectively.

The operation of the above control construction will now be described.When the recording signal is inputted to the interface 1700, therecording signal is converted into recording data for printing betweenthe gate array 1704 and MPU 1701. The motor drivers 1706 and 1707 aredriven, the recording head is driven in accordance with the recordingdata sent to the head driver 1705, and the print is performed.

The component elements of the invention can be assembled into thecontrol construction of the ink jet printer as mentioned above. It willbe obviously understood that the invention is not limited to the laserbeam printer but can be also applied to the above ink jet printer or thelike.

What is claimed is:
 1. A print data processing apparatus receiving printdata and switching between print data processing methods for processingprint data in accordance with the contents of the received print data,said apparatus comprising: receiving means for receiving print data; andprocessing operation determining means for switching between a firstprint data processing method of processing print data which does notcomprise a job packet and a second print data processing method ofprocessing print data which comprises a job packet, in accordance withwhether the print data received by said receiving means comprises a jobpacket, wherein said printing apparatus can be selectively placed in astate in which both the first and second print data processing methodsare used for processing print data and in a state in which either one orthe other of the first and second print data processing methods isforcibly selected and used for processing print data.
 2. An apparatusaccording to claim 1, wherein said receiving means can receive the printdata which comprises the job packet and the print data which does notcomprise the job packet.
 3. An apparatus according to claim 1, furthercomprising data discriminating means for discriminating whether theprint data received by said receiving means comprises the job packet orthe print data does not comprise the job packet.
 4. An apparatusaccording to claim 3, wherein the print data comprising the job packethas identification information in the header portion of the print data,and wherein said data discriminating means discriminates whether theidentification information is included in the print data received bysaid receiving means or not, thereby discriminating whether the printdata is print data comprising the job packet or print data which doesnot comprise the job packet.
 5. A print data processing apparatusreceiving print data and switching between print data processing methodsfor processing print data in accordance with the contents of thereceived print data, said apparatus comprising: receiving means forreceiving print data; processing operation determining means forswitching between a first print data processing method of processingprint data which does not comprise a job packet and a second print dataprocessing method of processing print data which comprises a job packet,in accordance with whether the print data received by said receivingmeans comprises a job packet; and mixture data discriminating means fordiscriminating whether or not the print data which does not comprise ajob packet and the print data which comprises a job packet mixedly existin the print data received by said receiving means, wherein saidprocessing operation determining means switches the print dataprocessing method in accordance with the mixture print data on the basisof a discrimination result of said mixture data discriminating means. 6.An apparatus according to claim 4, further comprising mixture datadiscriminating means for discriminating whether or not the print datawhich does not comprise the job packet and the print data whichcomprises the job packet mixedly exist in the print data received bysaid receiving means or not, wherein said processing operationdetermining means switches the print data processing method inaccordance with the mixture print data on the basis of a discriminationresult of said mixture data discriminating means.
 7. An apparatusaccording to claim 6, wherein when it is determined by said datadiscriminating means that the print data received by said receivingmeans does not comprise the job packet and when it is decided by saidmixture data discriminating means that the job packet mixedly exists inthe print data, said processing operation determining means switches theprint data processing method in a manner such that the print data, untilit is determined that the print data which comprises the job packetexists, is processed by the first print data processing method and theprint data after it has been determined that the print data whichcomprises the job packet exists is processed by the second print dataprocessing method.
 8. An apparatus according to claim 7, wherein, in acase where the identification information is included in the print datareceived by said receiving means, said mixture data discriminating meansdetermines that the print data which comprises the job packet mixedlyexists.
 9. A print data processing apparatus receiving print data andswitching between print data processing methods for processing printdata in accordance with the contents of the received print data, saidapparatus comprising: receiving means for receiving print data;processing operation determining means for switching between a firstprint data processing method of processing print data which does notcomprise a job packet and a second print data processing method ofprocessing print data which comprises a job packet in accordance withwhether the print data received by said receiving means comprises a jobpacket; and selecting means for enabling the operation of said firstprint data processing method to be forcibly selected.
 10. An apparatusaccording to claim 1, further comprising job pre-processor means forextracting data regarding a printing process from the print data whichcomprises a job packet and storing it into predetermined data storingmeans.
 11. An apparatus according to claim 1, further comprisinginformation managing means for, when management data which comprises ajob packet is received by said receiving means, rewriting equipmentinformation or print job information of the print data processingapparatus stored in information storing means or generating reply dataon the basis of the equipment information stored in said informationstoring means.
 12. An apparatus according to claim 11, furthercomprising channel control means for transferring data to saidinformation managing means in a case where the data received by saidreceiving means is the management data which comprises the job packetand for transferring the data to said processing operation determiningmeans in a case where said received data is the print data.
 13. Aprinting system having a print data processing apparatus and a hostcomputer to transmit print data to said print data processing apparatus,said print data processing apparatus receiving print data and switchingbetween print data processing methods for processing print data inaccordance with the contents of the received print data, said print dataprocessing apparatus comprises: receiving means for receiving printdata; and processing operation determining means for switching between afirst print data processing method of processing print data which doesnot comprise a job packet and a second print data processing method ofprocessing print data which comprises a job packet, in accordance withwhether the print data received by said receiving means comprise a jobpacket, wherein said printing apparatus can be selectively placed in astate in which both of the first and second print data processingmethods are used an in a state in which either one or the other of thefirst and second print data processing methods is forcibly selected andused for processing print data, and said host computer comprises jobpacket generating means for generating the print data converted into thejob packet.
 14. A print control method of receiving print data andswitching between print data processing methods for processing printdata in accordance with the contents of the received print data, saidmethod comprising: a receiving step, of receiving print data; aprocessing operation determining step, of switching between a firstprint data processing method of processing print data which does notcomprise a job packet and a second print data processing method ofprocessing print data which comprises a job packet, in accordance withwhether the print data received in said receiving step comprises a jobpacket; and selectively placing a printing apparatus performing saidprint control in a state in which both the first and second print dataprocessing methods are used and in a state in which either one or theother one of the first and second print data processing methods isforcibly selected and used for processing print data.
 15. A methodaccording to claim 14, wherein, in said receiving step, the print datawhich comprises the job packet and the print data which does notcomprise the job packet can be received.
 16. A method according to claim14, further comprising a data discriminating step, of discriminatingwhether the print data received in said receiving step is the print datawhich comprises the job packet or the print data which does not comprisethe job packet.
 17. A method according to claim 16, wherein the printdata which comprises the job packet has identification information inthe header portion of the print data, and wherein, in said datadiscriminating step, by discriminating whether or not the identificationinformation is included in the print data received in said receivingstep the received print data is discriminated as to whether it comprisesthe job packet or does not comprise the job packet.
 18. A print controlmethod of receiving print data and switching between print dataprocessing methods for processing print data in accordance with thecontents of the received print data, said method comprising: a receivingstep, of receiving print data; a processing operation determining step,of switching between a first print data processing method of processingprint data which does not comprise a job packet and a second print dataprocessing method of processing print data which comprises a job packet,in accordance with whether the print data received in said receivingstep comprises a job packet; and a mixture data discriminating step, ofdiscriminating whether or not print data which does not comprise a jobpacket and print data which comprises a job packet mixedly exist in theprint data received in said receiving step, wherein in said processingoperation determining step, the print data processing method is switchedin accordance with the mixture print data on the basis of adiscrimination result in said mixture data discriminating step.
 19. Amethod according to claim 17, further comprising a mixture datadiscriminating step, of discriminating whether or not print data whichdoes not comprise the job packet and print data which comprises the jobpacket mixedly exist in the print data received in said receiving step,wherein, in said processing operation determining step, the print dataprocessing method is switched in accordance with the mixture print dataon the basis of a discrimination result in said mixture datadiscriminating step.
 20. A method according to claim 19, wherein when itis determined in said data discriminating step that the print datareceived in said receiving step does not comprise the job packet andwhen it is decided in said mixture data discriminating step that the jobpacket mixedly exists in the print data, in said processing operationdetermining step, the print data processing method is switched in amanner such that the print data, until it is determined that the printdata which comprises the job packet exists, is processed by said firstprint data processing method and the print data after it has beendetermined that the print data which comprises the job packet exists isprocessed by said second print data processing method.
 21. A methodaccording to claim 20, wherein in said mixture data discriminating step,in a case where the identification information is included in the printdata received in said receiving step, it is determined that the printdata which comprises the job packet mixedly exists.
 22. A print controlmethod of receiving print data and switching between print dataprocessing methods for processing print data in accordance with thecontents of the received print data, said method comprising: a receivingstep, of receiving print data; a processing operation determining step,of switching between a first print data processing method of processingprint data which does not comprise a job packet and a second print dataprocessing method of processing print data which comprises a job packet,in accordance with whether the print data received in said receivingstep comprises a job packet; and a selecting step, of enabling theoperation of the first print data processing method to be forciblyselected.
 23. A method according to claim 14, further comprising a jobpre-processor step, of extracting data regarding a printing process fromthe print data which comprises the job packet and storing it into datastoring means.
 24. A method according to claim 14, further comprising aninformation managing step, of, when management data which comprises ajob packet is received in said receiving step, rewriting equipmentinformation or print job information of the printing apparatus stored ininformation storing means or generating reply data on the basis of theequipment information stored in said information storing means.
 25. Amethod according to claim 24, further comprising a channel control step,of transferring the data to information managing means of the printingapparatus in a case where the data received in said receiving step isthe management data which comprises the job packet and transferring thedata to processing operation determining means of the printing apparatusin the case wherein the received data is the print data.
 26. A printingsystem control method constructed by a print control method, for usewith a printing apparatus, and a host computer control method, for usewith a host computer, of transmitting print data to be used in saidprint control method, wherein said print control method comprises: areceiving step, of receiving the print data; and a processing operationdetermining step, of switching between a first print data processingmethod of processing print data which does not comprise a job packet anda second print data processing method of processing print data whichcomprises a job packet, in accordance with whether the print datareceived in said receiving step comprises a job packet, wherein theprinting apparatus can be selectively placed in a state in which both ofthe first and second print data processing methods are used and in astate in which either one or the other of the first and second printdata processing methods is forcibly selected and used for processing theprint data, and said host computer control method comprises a job packetgenerating step, of generating the print data converted into the jobpacket.
 27. A computer readable recording medium storing a programexecuting a print control method of receiving print data and switchingbetween print data processing methods for processing print data inaccordance with the contents of the received print data, said programcomprises: code for a receiving step, of receiving print data; and codefor a processing operation determining step, of switching between afirst print data processing method of processing print data which doesnot comprise a job packet and a second print data processing method ofprocessing print data which comprises a job packet, in accordance withwhether the print data received by said receiving code comprises a jobpacket; and selectively placing a printing apparatus performing saidprint control method in a state in which both of the first and secondprint data processing methods are used and in a state in which eitherone or the other of the first and second print data processing methodsis forcibly selected and used for processing the print data.
 28. Amedium according to claim 27, wherein, the print data which comprisesthe job packet and the print data which does not comprise the job packetcan be received by said receiving code.
 29. A medium according to claim27, wherein said program further comprises code for a datadiscriminating step, of discriminating whether the print data receivedby said receiving code is print data which comprises the job packet orprint data which does not comprise the job packet.
 30. A mediumaccording to claim 29, wherein the print data which comprises the jobpacket has identification information in the header portion of the printdata, and wherein, by said data discriminating code discriminatingwhether or not the identification information is included in the printdata received by said receiving code, the received print data isdiscriminated as to whether it it comprises the job packet or does notcontain the job packet.
 31. A computer readable recording medium storinga program executing a print control method of receiving print data andswitching between print data processing methods for processing printdata in accordance with the contents of the received print data, saidprogram comprises: code for a receiving step, of receiving print data;code for a processing operation determining step, of switching between afirst print data processing method of processing print data which doesnot comprise a job packet and a second print data processing method ofprocessing print data which comprises a job packet, in accordance withwhether the print data received by said receiving code comprises a jobpacket; and code for a mixture data discriminating step, ofdiscriminating whether or not the print data which does not comprise ajob packet and the print data comprises a job packet mixedly exist inthe print data received by said receiving code. wherein, in saidprocessing operation determining code, the print data processing methodis switched in accordance with the mixture print data on the basis of adiscrimination result by said mixture data discriminating code.
 32. Amedium according to claim 30, wherein said program further comprisescode for a mixture data discriminating step, of discriminating whetheror not the print data which does not comprise the job packet and theprint data which does comprise the job packet mixedly exist in the printdata received by said receiving code, and wherein said processingoperation determining code switches the print data processing method inaccordance with the mixture print data on the basis of a discriminationresult by said mixture data discriminating code.
 33. A medium accordingto claim 32, wherein when it is determined by said data discriminatingcode that the print data received by said receiving code does notcomprise the job packet and when it is decided by said mixture datadiscriminating code that the job packet mixedly exists in the printdata, said processing operation determining code switches the print dataprocessing method in a manner such that the print data, until it isdetermined that the print data which comprises the job packet exists, isprocessed by the first print data processing method and the print dataafter it has been determined that the print data comprises the jobpacket exists is processed by the second print data processing method.34. A medium according to claim 33, wherein, said mixture datadiscriminating code, in a case where identification information isincluded in the print data received by said receiving code, determinesthat the print data which comprises a job packet mixedly exists.
 35. Acomputer readable recording medium storing a program executing a printcontrol method of receiving print data and switching between print dataprocessing methods for processing print data in accordance with thecontents of the received print data, said program comprises: code for areceiving step, of receiving print data; code for a processing operationdetermining step, of switching between a first print data processingmethod of processing print data which does not comprise a job packet anda second print data processing method of processing print data whichcomprises of a job packet, in accordance with whether the print datareceived by said receiving means comprises a job packet; and code for aselecting step, of enabling the operation of the first print dataprocessing method to be forcibly selected.
 36. A medium according toclaim 27, wherein said program further comprises code for a jobpre-processor step, of extracting data regarding a printing process fromthe print data which comprises the job packet and storing it intopredetermined data storing means.
 37. A medium according to claim 27,wherein said program further comprises code for an information managingstep, of, when management data which comprises a job packet is receivedby said receiving code, rewriting equipment information or print jobinformation of the printing apparatus stored in information storingmeans or generating reply data on the basis of the equipment informationstored in the information storing means.
 38. A medium according to claim37, wherein said program further comprises code for a channel controlstep, of transferring data to information managing means of the printingapparatus in a case where the data received by said receiving code isthe management data which comprises the job packet and transferring thedata to processing operation determining means of the printing apparatusin a case where the received data is the print data.
 39. A computerreadable recording medium storing a program allowing a computer toexecute a printing system control method constructed by a print controlmethod of controlling a printing apparatus and a host computer controlmethod of controlling a host computer to transmit print data to theprinting apparatus is stored, wherein said print control methodcomprises: a receiving step, of receiving print data; and a processingoperation determining step, of switching between a first print dataprocessing method of processing print data which does not comprise a jobpacket and a second print data processing method of processing printdata which comprises a job packet, in accordance with whether the printdata received in said receiving step comprises a job packet, wherein theprinting apparatus can be selectively placed in a state in which both ofthe first and second print data processing methods are used and in astate in which either one of the first and second print data processingmethods is forcibly selected and used for processing the print data, andsaid host computer control method comprises a job packet generating stepof generating the print data converted into the job packet.
 40. A printdata processing apparatus receiving print data and switching betweenprint data processing methods for processing print data in accordancewith the contents of the received print data, said apparatus comprising:a receiver unit, adapted for receiving print data; and a processor unit,adapted for switching between a first print data processing print datawhich does not comprise a job packet and a second print data processingmethod of processing print data which comprises a job packet, inaccordance with whether the print data received by said receiver unithas identification information in the header portion of the print data.41. An apparatus according to claim 40, wherein when the received printdata contains no identification information, said processor unitanalyzes whether data subsequently received contains identificationinformation in the header portion of the data.
 42. An apparatusaccording to claim 40, wherein the received print data has noidentification information, said processor unit analyzes whether datasubsequently received has identification information in the headerportion.
 43. An apparatus according to claim 40, wherein theidentification information comprises a value indicating a job start.